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building my first stroker looking for some anwsers
Posted: September 20th, 2010, 4:18 pm
by aurichbb7
I am going to be building a 4.5 to put in my 97 cherokee
91-95 block (no bore or machine work)
91-95 head (no material removed)
258 crank
258 rods
4.0 pistons
91-95 cam
Header
full 2.5 exhaust and high flow cat
99 intake w/throttle body spacer
I ran the DCR/SCR calculator and came up with: SCR=9.79:1, DCR=8.1:1, .0725 Quench, 60.95 IVCA
-I would like to know if the fact that I am using the 91-95 motor, head and cam as a base will that cause any problems with me using the ECU and wiring in my 97 to run it?
-Do my CR #'s look acceptable?
-am I missing out on alot of power gain not going with a after market cam?
-Do I need to upgrade the oil pump?
-Do I need to upgrade my injectors?
-In my case would it be beneficial to port and polish the head?
-would it be benefical to bore my throttle body/spacer?
I use the truck as a daily driver and wheel once in awhile. I have 32's with a 5 inch lift and soon will have 4:10 gears but am rocking 3.55's now. Any insight would be greatly appreciated.
Ben
Re: building my first stroker looking for some anwsers
Posted: September 21st, 2010, 2:04 pm
by Cheromaniac
aurichbb7 wrote:I ran the DCR/SCR calculator and came up with: SCR=9.79:1, DCR=8.1:1, .0725 Quench, 60.95 IVCA
-I would like to know if the fact that I am using the 91-95 motor, head and cam as a base will that cause any problems with me using the ECU and wiring in my 97 to run it? No.
-Do my CR #'s look acceptable? A little high but manageable.
-am I missing out on alot of power gain not going with a after market cam? Not a huge power gain but with the high static CR, I think that going for a longer duration cam than stock would be adviseable to prevent pinging problems.
-Do I need to upgrade the oil pump? A new stock pump would do fine.
-Do I need to upgrade my injectors? Maybe. Your stock 23.3lb'ers will be marginal.
-In my case would it be beneficial to port and polish the head? Always a good thing.
-would it be benefical to bore my throttle body/spacer? A 62mm bore size is probably optimal.
Re: building my first stroker looking for some anwsers
Posted: May 18th, 2011, 2:20 pm
by sboone14
I'm building my first stroker for my daughter's '88 YJ, and I have some questions. Here's what we have:
4.2 from '88 YJ
4.0 from '90 Cherokee (not best engine, but best price. "Free") Complete with all wiring, ecm, and cherokee.
Both engines have a lot of miles, so we are starting at the machine shop. The plan is to do the poor man's build using the 4.0 block and head with the 4.2 crank and rods. This will be my daughter's daily driver, so we are trying to improve drive ability by switching to efi. The stroker part was an after thought from doing research on the efi conversion. I guess I'm not really following some of the particulars of doing this project. I understand there are some additional modifications I have to make since the donor is a cherokee, like the cooling fan, but are there any others?
Harmonic Balancer - have someone cut 10mm off the back of the 4.0 balancer to use as a spacer for the 4.2?
Flexplate - use 4.2 flex plate with crank sensor ring from 4.0?
Injectors - 24# ford blue or gm lt1?
Crank position sensor - modify transmission bell housing to accept sensor in same position as donor?
Camshaft - stock or aftermarket (which will provide best usable power and economy?)
We are trying to do as much work as we can on our own to save money, and to teach her about mechanics, but there are some things I realize we are unable to do simply because we don't have the proper tools or skills.
I appreciate any assistance you can give. It seems the more I research and read, the more confusing it gets.
Thank you,
Re: building my first stroker looking for some anwsers
Posted: May 18th, 2011, 4:23 pm
by jbxx
Don't worry we have all been there, some of us are still there!
I have learned a lot from going over the projects threads, have a look!
J.B.
Re: building my first stroker looking for some anwsers
Posted: May 18th, 2011, 4:28 pm
by gradon
You can either modify the bellhousing to install the crank sensor or buy Hesco's crank pulley w/ sensor system:
http://www.hesco.us/shop.asp?action=det ... catId=7902 . A bigger cam would be nice, but not necessary. The 90 renix blocks are reputed to have higher nickle content and thicker cylinder walls. 90 renix fuel rail w/ return are rated at 39psi, so you'll want an injector rated 24#@39psi(older ford blue tops). The 24#@43.5psi lt1s would flow a little less at 39psi, but still might work well. You'll want to have the renix TB bored out to 60mm(Jeff Leigh @ strokedjeep.com).
Re: building my first stroker looking for some anwsers
Posted: May 18th, 2011, 7:24 pm
by sboone14
Thanks for the info. After looking at the price of the hesco kit, I think I'll try modifying my bellhousing. Unless I win the lottery before finishing the build.
Re: building my first stroker looking for some anwsers
Posted: May 23rd, 2011, 9:16 am
by sboone14
You guys have been a lot of help already. Here's another question I can't seem to find the answer to in the archives. Since I am putting FI on a YJ that had a carb, I have to add an electric fuel pump and pressure regulator. Can someone give me an idea of what pump to get or what years tanks with stock pump to look for?
Thanks again for sharing your vast knowledge with my tiny brain.
Shannon
Re: building my first stroker looking for some anwsers
Posted: May 23rd, 2011, 9:33 am
by gradon
I would think that a tank and pump from a 91-95 YJ would be the easiest to adapt.
Re: building my first stroker looking for some anwsers
Posted: May 23rd, 2011, 1:46 pm
by YJason
gradon wrote:I would think that a tank and pump from a 91-95 YJ would be the easiest to adapt.
X2, you should be able to find a used one cheap with all the people that are extending there wheel bases in YJ's and going to fuel cells. It should bolt right in, and if you do go that route do a search on the 20 gallon upgrade or PM me.
Re: building my first stroker looking for some anwsers
Posted: May 24th, 2011, 10:11 pm
by AlexTJ
aurichbb7 wrote:
I ran the DCR/SCR calculator and came up with: SCR=9.79:1, DCR=8.1:1, .0725 Quench, 60.95 IVCA
-Do my CR #'s look acceptable? I have almost the same CRs as you (9.78:1 8.08:1) but with .052 quench. I run 91 at Kansas altitude (~1000' over sea level) and I have run 89 but it seems to run a bit messier, especially if its warmer out (75+).
-am I missing out on alot of power gain not going with a after market cam? Yes, my last stroker had a stockish comp cam in it and the difference between it and my lunati puts a huge smile on my face. The cam seems to put the power band in the sweet spot for my mostly highway/town use with occasional weekend wheeling. It actually pulls all the way to redline. Check out this thread for my estimation of the difference:
http://www.jeepstrokers.com/forum/viewt ... 502#p18502